Abstract： Objective To improve the current quality of the upper cervical spine finite element models in China by developing and validating an anatomically detailed three-dimensional hexahedral finite element model of the upper cervical spine for use in clinically relevant biomechanical research.Methods The finite element model was developed with detailed anatomy from 16-slice computed tomographic images of the occiput to the C3 with 0.5 mm thickness from a healthy male subject.The image data were saved in Dicom format,and then imported into the Mimics 10.01 software for reconstructing three-dimensional geometric model of the upper cervical spine.By using the ICEM software,the C0-C3 three-dimensional hexahedral finite element model was reconstructed,with the thickness of the endplates set to 0.2 mm,the gap of facet joints set to 0.5 mm and defined as sliding contact with the friction coefficient being 0.1.Then,the Hypermesh V10.0 software was employed to adjust the mesh quality,load the ligament,and preliminarily develop a three-dimensional hexahedral finite element model of the upper cervical spine (C0-C3).Subsequently,the movements of bending forward,dorsal flexion,rotation,lateroversion were generated through the assignment of materials,the constraint of boundary and the stimulation of models.The resultant data were imported into the ABAQUS 6.11 software for the analysis of the three-dimensional motion of each vertebral level.Finally,the stress nephogram of the model's three-dimensional range of motion (ROM) and stress distribution were compared with in vitro experiments and other published data for efficacy validation.Results An anatomically detailed three-dimensional hexahedral finite element model of the upper cervical spine was developed,which consisted of 30 550 nodes and 41 909 elements.The ROM and stress distribution coincided with the data from published literatures.Conclusion The finite element model of the upper cervical spine developed in this study appears to show high authenticity for use in clinically relevant biomechanic studies.